title: DNA microarray-based genotyping of Chlamydophila psittaci strains from culture and clinical samples.
abstract: The avian and human pathogen Chlamydophila (C.) psittaci represents a genetically heterogeneous species. To facilitate epidemiological surveys, more rapid yet highly specific molecular tests are needed. Currently used typing methods, i.e. serotyping and PCR-RFLP, have only limited sensitivity and are incapable of covering the wide spectrum of naturally occurring types of C. psittaci strains. In the present study, a new DNA microarray assay based on the ArrayTube (AT) technology was used to genotype C. psittaci in 98 isolates and 23 clinical tissue samples. The present array carries 35 oligonucleotide probes derived from variable domains 2 and 4 of the ompA gene. The assay proved highly sensitive, allowing correct genotyping of DNA from 2 inclusion-forming units. The results of DNA microarray genotyping of cultured strains proved highly concordant with the data from PCR-RFLP typing and serotyping. Sequencing of the ompA gene served as the reference test to verify the accuracy of AT genotyping results. In 15 instances (15.3%), strains were successfully typed by the AT assay, while serotyping and/or PCR-RFLP genotyping failed to produce unambiguous results. Eleven of these samples were ompA sequenced to confirm the AT findings. In addition to the currently accepted nine ompA genotypes, the microarray test was shown to recognise new provisional genotypes, such as Mat116 and YP84. In conclusion, the new AT assay proved to be suitable for rapid, sensitive and reproducible genotyping of C. psittaci strains and can be recommended for routine diagnosis.
authors.affiliation: Friedrich-Loeffler-Institut (Federal Research Institute for Animal Health), Institute of Molecular Pathogenesis, Jena, Germany. konrad.sachse@fli.bund.de
authors.forename: Konrad
authors.initials: K
authors.lastname: Sachse
authors.forename: Karine
authors.initials: K
authors.lastname: Laroucau
authors.forename: Fabien
authors.initials: F
authors.lastname: Vorimore
authors.forename: Simone
authors.initials: S
authors.lastname: Magnino
authors.forename: Jens
authors.initials: J
authors.lastname: Feige
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Müller
authors.forename: Steffen
authors.initials: S
authors.lastname: Kube
authors.forename: Helmut
authors.initials: H
authors.lastname: Hotzel
authors.forename: Evelyn
authors.initials: E
authors.lastname: Schubert
authors.forename: Peter
authors.initials: P
authors.lastname: Slickers
authors.forename: Ralf
authors.initials: R
authors.lastname: Ehricht
mesh_terms: D002691:Chlamydophila psittaci / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics*; D005838:Genotype; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D004269:DNA, Bacterial